Recently, stirling engines have been increasingly focused on, and its purpose is to recover exhaust heat of internal combustions provided in vehicles such as automobiles, buses, or trucks, or exhaust heat of factories. High thermal efficiency of the stirling engine is expected. Further, the stirling engine can use low-temperature difference alternative energies such as solar heat, geothermal heat, or exhaust heat, because the stirling engine is an external combustion which heats the working fluid from its outside. The stirling engine has an advantage of saving energy.
Patent Documents 1 to 6, considered relative to structures of the present invention, disclose techniques of the stirling engines.